Irrigation device and method

ABSTRACT

A subsurface irrigation device of the type comprising a rigid pipe, one end of which is reversibly connected to a pressurized source of irrigation fluid and the other end for insertion into the ground. A substantially blunt tip at the ground penetrating end is provided with orifices capable of releasing, under the control of a valve, a plurality of streams of pressurized fluid at one or more acute angles with respect to the pipe axis, providing improved ground penetration while minimizing root damage.

CROSS-REFERENCE

The present application claims priority from U.S. Provisional PatentApplication No. 60/808,782 filed May 25, 2006, the contents of which arehereby incorporated in their entirety by reference, and which is notadmitted to be prior art by its mention in the background.

FIELD OF THE INVENTION

The invention relates to an apparatus and method for injecting a fluidinto soil, and more particularly to a device and method for use in thesubsurface irrigation of plant roots.

BACKGROUND OF THE INVENTION

Subsurface irrigation of plant roots is well-known to reduce surfaceevaporation and to be useful for efficiently providing water,fertilizer, and other beneficial chemicals directly to the roots ofplants with low losses, good control, reduced runoff, and reduced costs.

A number of devices for subsurface irrigation are known. U.S. Pat. No.749,758 to Templeton discloses a device with a single nozzle or cuttingteeth to aid in soil penetration; U.S. Pat. No. 1,937,172 to Starner etal. discloses a device with a sharp, wedge-shaped tip, the twisting ofwhich aids in soil penetration; U.S. Pat. No. 2,333,727 to Lucasdiscloses an tip for soil penetration comprising a relatively sharpprong that aids in penetrating the soil ahead of the irrigating openingsin the tube; U.S. Pat. No. 4,170,948 to Strickland discloses a devicehaving a tapered single nozzle which is inserted into soil with the aidof a vibrating device attached to the pipe and powered by the waterflow; and U.S. Pat. No. 4,697,952 to Maddock teaches the drilling of anirrigation hole using a down tube with a single outlet at its tip.

These approaches suffer from the drawback that the soil penetration ofthese devices attributable to the action of water flow upon the soil isrelatively inefficient, requiring either a sharp tip or other additionalmeans such as a vibrating device or cutting teeth to aid in penetratingthe soil. However, sharp tips or cutting teeth readily damage plantroots thereby promoting disease, and damage buried structures such ascables. The need for additional devices such as vibrating devices iscumbersome, expensive and renders such devices unattractive for domesticuse. Inefficient soil penetration also means that the tubes of thesedevices should be strongly constructed in order to withstand the greaterforces that must be applied to them, thereby increasing weight andexpense.

Notwithstanding the existence of a variety of subsurface irrigationdevices in the prior art, there is a continuing need for more efficientand lightweight devices better adapted to domestic use and moreenjoyable to use, and the present invention substantially fulfills theseneeds. All this and more will become apparent to one of ordinary skillupon reading the disclosure, drawings, statements, and claims appendedhereto.

SUMMARY OF THE INVENTION

The present invention is directed to device and method for subsurfaceirrigation of soil and plant roots. In particular, the inventionprovides an irrigation device capable of insertion into soil to anydesired irrigation depth with a minimum of effort, in which insertion issubstantially aided by the flow of irrigation fluid dispensed from anovel and improved nozzle.

In a first embodiment, an irrigation device according to the presentinvention comprises a rigid tube comprising, at its proximal end, ameans, such as a threaded fitting or compression fitting, for attachingto a source of pressurized fluid, for example a source of irrigationwater from a mains supply, or a source that is pumped from portablecontainer or from a large container attached to a vehicle. The distalend of the tube comprises a tip that seals said end but for a pluralityof orifices disposed through the tip that permit the pressurized fluidin the tube to flow from said end at one or more acute angles relativeto the major longitudinal axis of the tube. The device further comprisesa means to regulate the flow of fluid within the tube, such as a ballvalve or other suitable valve.

To minimize damage to plant roots or other sensitive buried structuressuch as buried cables or the like, the tip is substantially blunt, forexample having a convex or hemispherical or other non-sharp outersurface.

The orifices are positioned to release more than one stream of thepressurized fluid. In particular, improved soil penetration is obtainedfrom a device in which the openings are positioned to produce streams atone or more acute angles with respect to the major longitudinal axis ofthe pipe. Without thereby being limited by theory, it is believed thatturbulence caused by the plurality of streams aids in the soilpenetrating characteristics of the device compared to prior art devices.

In use, the steps of the method of the present invention can beperformed in orders other than the order set forth below. The methodcomprises attaching a source of pressurized fluid to the attachmentmeans of a device according to the present invention, for example bythreadingly engaging a hose-pipe to a receptacle at the proximal end ofthe device; adjusting the valve means to provide streams of pressurizedliquid from the tip; contacting the soil with the distal end of thedevice with downward pressure, such as for example gentle hand pressure;permitting the device to penetrate the soil to the desired,predetermined irrigation depth; and adjusting the valve means to providea predetermined flow of fluid for a predetermined time in order toaccomplish subsurface irrigation. For example, a high rate of irrigationcan be obtained by adjusting the valve means to the point thatirrigation fluid ceases to backflow to the surface.

It should be understood that an advantage of the present device is thatthe degree of downward pressure required to penetrate the soil islessened by the soil displacing properties of the tip. The turbulentflow of pressurized irrigation fluid efficiently loosens and displacesthe soil from the path of the tip, thereby reducing the requireddownward pressure. Further, visual cues such as irrigation fluidsubsequently emerging at the soil surface can optionally be used toindicate the completion of irrigation.

It is therefore an object of the present invention to provide a deviceand method for subsurface irrigation of plant roots such as tree rootsin which damage to the roots or other sensitive subsurface structures isminimized.

It is a further object of the present invention to provide a devicecapable of insertion to any desired irrigation depth with minimalphysical effort and without the need for prior drilling of irrigationholes or the prior placement of permanent irrigation lines.

It is a further object to provide a subsurface irrigation device inwhich soil penetration is substantially aided by provision of a noveltip capable of producing multiple streams of fluid at one or more acuteangles with respect to the major longitudinal axis of the tube, wherebya turbulent flow is produced upon contact with the soil and efficientsoil penetration is obtained.

It is yet a further object to provide an efficient subsurface irrigationdevice that can be used to introduce fertilizer, pesticide, herbicide,or the like, at desired subsurface locations without loss of material orpollution due to surface application and runoff.

Thus, in a second embodiment, the irrigation device according to thepresent invention further comprises a reservoir for holding a pesticide,herbicide, insecticide, or the like, the reservoir being in fluidcommunication with the interior of the tube, either directly or via asecond valve means, and whereby the reservoir fluid is drawn into andmixed with the irrigation fluid during operation of the device.

In a third embodiment, the tube of an irrigation device according to thepresent invention further comprises a detachable coupling whereby thelength of the tube can be adjusted by inserting or removing tubesections of selectable length to adjust that length of the device inorder to adjust the depth of irrigation.

In a fourth embodiment, markings are provided on the exterior of thedevice to facilitate irrigation at a reproducible desired depth.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood with regard to the followingdescription, appended claims, and accompanying drawings where:

FIG. 1 shows a perspective view of an embodiment of a subsurfaceirrigation device according to the present invention.

FIG. 2 shows a perspective view of an alternative embodiment of thesubsurface irrigation device according to the present invention furthercomprising a reservoir for fertilizer, pesticide, herbicide, or thelike.

FIG. 3 shows selected views of the tip of an embodiment of thesubsurface irrigation device according to the present invention. A:longitudinal perspective view; B: longitudinal cross-sectional view; andC: end perspective view.

FIG. 4 shows a view of a subsurface irrigation device according to thepresent invention in use.

DETAILED DESCRIPTION

Certain exemplary but non-limiting embodiments of the present inventionare now described with reference to the attached drawings.

Referring now to FIG. 1, an irrigation device 100 according to thepresent invention is shown. The device 100 comprises rigid tube 110.Tube 110 comprises a proximal end 120 comprising attachment means 130for connecting the interior of the tube 110 to a source of pressurizedliquid, and a distal end 140 comprising a tip 145 having plurality ofopenings 150 that are further described with reference to FIG. 3. Tube110 can be constructed from any water-impermeable material of sufficientrigidity, strength and durability. The cross-sectional shape of tube 110is preferable circular, but other cross-sections can also be used. Thus,as used herein, the term “tube” encompasses, for example and withoutlimitation, oval, square, and triangular cross sections. In preferredembodiments, the tube is constructed from PVC, but other plastics,metals, fiber glass, and the like, can be used. The length of tube 110in preferred embodiments is from about 15″ to about 60″. The tube can beof unitary construction, or can be constructed by assembling discreteparts as shown in the embodiment of FIG. 1.

The improved soil penetrating properties of the present device meansthat lighter and less stiff materials can be used for the tube becausethe device can be inserted into soil without undue force. Thus, as usedherein, the term “rigid” refers to a self-supporting structure ofsufficient rigidity for use according to the methods herein. Forexample, it is not required that the tube be sufficiently rigid as notto deform in use. Standard PVC pipe, such as 0.5 inch i.d. PVC pipe, canbe used to form the pipe of a device of the present invention and isconsidered herein a “rigid tube” although it may deform to some extentin use.

Means 130 for attaching the proximal end of the tube to a source ofpressurized liquid are well-known in the art and can include, forexample, a threaded fitting, a snap-connector, a bayonet fitting, ashrink fit, or simply the insertion of the proximal end of the deviceinto a hose with or without a securing clip surrounding the hose. Bysuch means, a substantially leak-free connection can be formed wherebythe source of pressurized liquid and the interior of tube 110 are placedin fluid communication. For ease of handling, and to avoid bending andcrimping an attached hose, the pipe 110 optionally comprises a bend 160,such as a perpendicular bend, towards the proximal end 120.Notwithstanding bend 160, pipe 110 comprises a major longitudinal axis180, to which the directions of the streams of pressurized fluid emittedby the tip 145 are referenced.

A valve means 170 is provided to regulate and control the flow of liquidwithin tube 110. In the embodiment of FIG. 1, a ball valve is shown, buta variety of suitable valves are well known to those of skill in theplumbing and irrigation arts. Preferably, valves capable of incrementalregulation of the flow are used. For example, the valve means 170 can beoperated by a rotating handle or can be coupled to a trigger-typeactuator, whereby the flow is controlled by the degree of rotation ofthe handle, or the pressure applied to the trigger-type actuator,respectively. The valve can be manually operated or can, for example, beremotely operated using a solenoid valve. The position of the valvealong the tube is not particularly limited, and is preferably positionedbetween bend 160 and attachment means 130.

Optionally, tube 110 can further comprise a means for adjusting thelength of the tube, such as for example detachable coupling 190 forreversibly inserting an extension tube. A selection of insertable pipeportions can be provided having differing lengths and/or diameters,according to the depth of irrigation desired, the condition orcomposition of the soil, or other factors, and the selected portion(s)can used to extend tube 110 by means of their insertion and attachmentat the detachable coupling.

To aid in locating the desired depth of irrigation, the outer surface ofthe tube can optionally further comprise depth markings 195 such as, forexample, one-inch markings measured from openings 150.

Referring now to FIG. 2, a second exemplary irrigation device 200according to the present invention is shown further comprising areservoir 210 for fertilizer, pesticide, herbicide, or the like. Thereservoir 210 can be in the form of a plastic bottle or other suitablyshaped and constructed container, and can be clear or opaque.Optionally, reservoir 210 is affixed to the tube by any suitableattachment means, such as by straps 220, or by clamps, screws, bolts, orthe like, or by unitary molding of the reservoir 210 and the tube.Alternatively, the reservoir 210 is not mounted to the tube and can be areservoir such as a free-standing tank or a large tank mounted to avehicle.

Reservoir 210 is fluidly connected to the interior of the tube, forexample by pipe 230 at attachment point 240. Without being limited bytheory, in use the flow of fluid in tube 110 generates a reducedpressure or siphoning effect that draws liquid from reservoir 210, whichthereby become diluted and mixed to form the irrigating fluid.Alternatively and optionally, the liquid can be pumped or metered from areservoir into the tube, and a second valve 250 can be interposedbetween the reservoir 210 and the tube 110.

Referring now to FIG. 3, there are shown selected views 300 of the tip310 of an embodiment of the subsurface irrigation device according tothe present invention.

The longitudinal perspective view in FIG. 3A illustrates substantiallyblunt tip 310. The blunt tip preferably comprises a convex outersurface. Most preferably the outer surface of the tip is hemispherical.The substantially blunt tip is advantageous in avoiding damage to plantroots or other buried structures such as cables and the like. Disposedwithin and through tip 310 is a plurality of openings or orifices 320fluidly connecting the interior and exterior of the tip.

As shown in longitudinal cross-sectional view in FIG. 3B, the orificesare disposed and oriented to produce, in use, a plurality of streams ofliquid at one or more acute angles 330, 340 in a plurality of directions360, 370, 380, with respect to longitudinal axis 350 of the tube.Optionally, one of the openings 390 produces a stream of liquidcoincident with longitudinal axis 350. Other numbers and orientations oforifices can be used within the scope of the present invention. Forexample, the orifices can be arranged to produce a helical flow patternby offsetting the centerline of one or more orifices with respect tolongitudinal axis 350 of the tube. The term “acute” as used herein withrespect to both helical, non-helical, or other flow patterns, refers tothe condition that the angle subtended by the direction of a streamproduced by an orifice and any plane containing the longitudinal axis350 of the tube is less than 90 degrees. Preferably the acute angles330, 340 are from about 0 to about 45 degrees, and most preferable fromabout 0 to about 25 degrees. Preferably, the tip comprises from 2 toabout 20 orifices.

The plurality of orifices as described herein produces a turbulent flowwhen placed in contact with the soil, which improves ground penetration.

Operation and use of a subsurface irrigation device according to thepresent invention is shown in FIG. 4. If the device is to be used toirrigate the roots of a plant 420, the proximal end of the device isattached to a source of pressurized fluid 440 such as water, the secondend of the device is placed upon the surface of the soil 430 and theoperator exerts a moderate downward pressure on the device. Because ofthe turbulent flow emitted from the tip, the device readily penetratessoil to a predetermined irrigation depth. The downward pressure is thenbe removed, and the flow adjusted using the valve means to deliver apredetermined irrigation flow-rate for a predetermined time. It will beappreciated that the device can readily be moved from one irrigationposition to another with a minimum of time, effort and wasted fluid.

The device of the present invention provides a number of advantages overthe prior art. The enhanced soil penetrating properties of the devicemean that the device can be constructed of lighter materials and isthereby more portable and easier to use. The ability to easily move thedevice to irrigate at different subsurface locations means thatirrigating liquid is more efficiently applied, with less waste, andsurface losses due to evaporation are minimized. Polluting runoff ofgardening chemicals is also reduced. These advantages therefore providebenefits to the plants, the user, and the community.

Although the present invention has been described in considerable detailwith reference to certain preferred versions thereof, other versions arepossible and can be envisaged within the scope and spirit of the presentinvention. Therefore, the spirit and scope of the appended claims shouldnot be limited to the description of the preferred versions containedherein.

Now that the invention has been described:

1. An irrigation device for subsurface irrigation, the devicecomprising: a rigid tube comprising proximal and distal ends and a majorlongitudinal axis; means for attaching the proximal end of the tube to asupply of pressurized fluid; a substantially blunt tip mounted to thedistal end of the tube and comprising a plurality of orifices forreleasing a plurality of streams of the pressurized fluid at one or moreacute angles to the major longitudinal axis of the tube; and a valvemeans disposed between the proximal and distal ends of the tube forregulating the flow of the fluid within the tube.
 2. The irrigationdevice according to claim 1, in which the tube comprises a bend betweenthe valve means and the distal end.
 3. The irrigation device accordingto claim 1, in which the tip comprises a convex outer surface.
 4. Theirrigation device according to claim 3, in which the outer surface ofthe tip is substantially hemispherical.
 5. The irrigation deviceaccording to claim 1, in which said orifices comprise a central orificecapable of releasing a stream of the pressurized fluid along the majorlongitudinal axis of the tube.
 6. The irrigation device according toclaim 1, further comprising a reservoir capable of containing a secondfluid, the reservoir in fluid communication with the interior of thetube.
 7. The irrigation device according to claim 6, in which saidsecond fluid comprises a fertilizer, a pesticide, an herbicide, or amixture thereof.
 8. The irrigation device according to claim 6, furthercomprising a second valve means for regulating the flow of the secondfluid into the tube.
 9. The irrigation device according to claim 1, inwhich said acute angles are between 0 and about 45 degrees.
 10. Theirrigation device according to claim 9, in which said acute angles arebetween 0 and about 25 degrees.
 11. The irrigation device according toclaim 1, the tube further comprising means for adjusting the length ofthe tube.
 12. The irrigation device according to claim 11, wherein themeans for adjusting the length of the tube comprises a detachablecoupling disposed between the valve means and the tip for reversiblydetaching a portion of the tube, and one or more tube sections capableof insertion at the detachable coupling to adjust the length of saidtube.
 13. The irrigation device according to claim 12, in which thedetachable coupling is a compression fitting.
 14. The irrigation deviceaccording to claim 1, further comprising markings on the surface of thetube for indicating the depth of irrigation.
 15. The irrigation deviceaccording to claim 1, in which the number of orifices is from about 2 toabout
 20. 16. A method for subsurface irrigation, the method comprising:attaching a source of pressurized fluid to the attachment means of adevice according to claim 1; adjusting the valve means to providestreams of pressurized liquid from the tip; contacting the soil with thedistal end of the device with downward pressure; permitting the distalend of the device to penetrate the soil to a predetermined depth; andadjusting the valve means to provide a predetermined flow of the fluidfor a predetermined time, whereby subsurface irrigation is obtained.